A colossal iceberg twice the size of Manhattan has broken away from the end of Greenland's Petermann glacier. Another, even bigger, iceberg broke from the northerly glacier in 2010, and scientists had been keeping an eye on a crack near the glacier's tip for years, reports AP. "It's dramatic. It's disturbing," says University of Delaware professor Andreas Muenchow. "We have data for 150 years, and we see changes that we have not seen before. It's one of the manifestations that Greenland is changing very fast."
Glaciers naturally spawn icebergs, but the changes to Petermann since 2010 are unprecedented. "This is not part of natural variations anymore," says a NASA glaciologist. "The Greenland ice sheet as a whole is shrinking, melting, and reducing in size as the result of globally changing air and ocean temperatures, and associated changes in circulation patterns in both the ocean and atmosphere," says Muenchow, noting that northern Greenland and Canada have been warming five times faster than the average global temperature.